1. Celebrate Together
You don't have to love each other, but if you can get together without killing each other, try to let the child spend at least some time opening presents with both parents.
2. Follow the Custody Order
You may hate that you don't get the whole day, but don't break the order and prevent your ex from seeing the child. It hurts the child not to see the other parent, and the police showing up at your door will not put you in a good mood.
3. Don't Follow the Custody Order
I know what I just said, but use common sense. The Order says the exchange must be at 4, but your ex's great grandmother from the Ukraine is in town and wants to eat at 3:30. Let the child go for a few extra hours. It will cause less stress for the child, garner family good will and selfishly will mean that your ex owes you a solid.
4. Keep Old Traditions
For your child's whole life, you may have done a Christmas Eve run to look at all of the local lights. Getting together in the car for an hour may not be your idea of bliss, but showing your children that they are the most important people in both of your lives will go a long way to producing healthy, happy adults.
5. Make New Traditions
Don't be afraid to try something new. The holidays may feel less festive when an important person is no longer in the house. The loss of one holiday tradition could be the birth of a new one. Perhaps you can't bake fresh cookies like Mom, but you can make popcorn and hot chocolate for a Christmas Eve Movie night. Be creative, and remember to have fun.